CPU, that's frequently called just "processor", is an abbreviation for Central Processing Unit. This is the core of every laptop or computer or web server, because it executes all of the calculations and logical input/output operations. Although the performance of a website or an application relies on other things also, including the amount of physical memory or the connectivity of the web server, the rate at which a given processor performs determines how fast an app will be executed. Later-generation processors have several cores that can severely increase their overall power and efficiency, due to the fact that each and every core can take care of a number of processes individually or several cores can handle 1 process that needs a substantial processing power. Because every single core works at a specific speed, this architecture can be looked at as a number of individual processors working together.